1. Field of the Invention
This invention relates to the field of semiconductor processing, and more specifically, to a method for cleaning a processing chamber in order to remove dielectric film or deposited film buildup.
2. Background Information
In the manufacture of semiconductor devices many layers are deposited on semiconductor substrates using process chambers. Some process chambers may be plasma vapor deposition chambers, chemical vapor deposition chambers, etc. As the layers, for example nitride and oxide layers, are deposited on the semiconductor substrate(s) some of the deposition material may also be deposited on the inner surfaces of the process chamber. This deposition material builds up on the inner surfaces of the process chamber and may eventually begin to flake off thereby contaminating the substrates that are currently being processed within the chamber. Such contamination of the substrate(s) may cause reliability problems and even device failure in the devices being fabricated.
Because it is desirable to keep the substrates as free of particulates and contaminants as possible during processing, it is necessary to clean the process chamber and remove this deposition material buildup. Depending upon the particular deposition material being used and the thickness of the layer being deposited it may be desirable to clean the processing chamber after every couple hundred of wafers are processed.
One problem with cleaning the process chamber, especially when cleaning oxide and/or nitride buildup, is that the etchants used to remove the buildup may also etch the process kit. It should be noted that the term process kit is used throughout the present disclosure to refer to the inner workings of the processing chamber, for example, the susceptor, table, moving parts for transferring the substrates, etc. The etchant used to remove the buildup damages the process kit and may require that the process kit be replaced or repaired.
Repairing and/or replacing the parts of the process kit can be expensive in the cost of the parts alone. However, to a manufacturer it may also be expensive in the amount of down time that is required to repair the processing chamber. Increased down time may decrease the efficiency and the throughput of the manufacturer's entire line.
Thus, what is needed is a method for removing the deposition material buildup from the inner surfaces of the processing chamber without damaging the process kit.